There is an ongoing scientific discussion about the safety of long term cell phone use. The primary question is whether or not long term exposure to non-ionizing radiation can increase the risk of brain cancer. There are further questions about whether or not such radiation can cause any health problems or symptoms.
As with any complex area of scientific research, perhaps the best way to evaluate the question is to put together a panel of experts to review all the existing evidence and then come up with a consensus opinion about that evidence. This is no guarantee of being right – the primary issue that tends to come up with such expert panels is that they were systematically biased toward one side of the debate. But assuming no major asymmetry in the constitution of an expert panel, they are an excellent way to evaluate the current state of the evidence on a specific question. Even better, of course, is when multiple independent panels all agree.
Recently an expert panel for the UK’s Health Protection Agency (HPA) reviewed the evidence for cell phone safety concluded that there is no clear evidence for any harm. This is good news. Their findings are similar to other reviews of the evidence, although often there is a difference in emphasis. For example, last year the International Agency for Research on Cancer (IARC) reviewed the same evidence and concluded that:
“the evidence, while still accumulating, is strong enough to support a conclusion and the 2B classification. The conclusion means that there could be some risk, and therefore we need to keep a close watch for a link between cell phones and cancer risk.”
They are not really saying anything different from the HPA – both groups concluded that there is no clear evidence of risk, but that further monitoring is prudent. The HPA, however, chose to emphasize that there is no conclusive evidence of risk, while the IARC chose to emphasize that there is no conclusive evidence that there is no risk. There classification means that there may or may not be a risk, but further research is warranted. Meanwhile the FDA has concluded that: “the weight of scientific evidence has not linked cell phones with any health problems.” The Federal Communications Commission has this to say:
“There is no scientific evidence that proves that wireless phone usage can lead to cancer or a variety of other problems, including headaches, dizziness or memory loss. However, organizations in the United States and overseas are sponsoring research and investigating claims of possible health effects related to the use of wireless telephones.”
These all sound like variations of the same conclusion – there is no clear evidence of harm or risk, but we should continue to do research and monitor the results. Overall there is more caution when children are concerned, because there are fewer studies, children’s heads are smaller, and if cell phone use is started at a young age then lifetime use will be greater. Still there is no evidence of harm, but there are a priori reasons for greater caution.
Getting back to the new review by the HPA, here are their key conclusions:
- The evidence suggests that RF field exposure below guideline levels does not cause symptoms in humans and that the presence of RF fields cannot be detected by people, including those who report being sensitive to RF fields.
- A large number of studies have now been published on cancer risks in relation to mobile phone use. Overall, the results of studies have not demonstrated that the use of mobile phones causes brain tumours or any other type of cancer.
- As mobile phone technology has only been in widespread public use relatively recently, there is little information on risks beyond 15 years from first exposure. It is therefore important to continue to monitor the evidence, including that from national brain tumour trends. These have so far given no indication of any risk.
- Studies of other RF field exposures, such as those at work and from RF transmitters, have been more limited but have not given evidence that cancer is caused by these exposures.
- Research on other potential long-term effects of RF field exposures has been very limited, but the results provide no substantial evidence of adverse health effects; in particular for cardiovascular morbidity and reproductive function.